VBCS 30/20/250 Triple CI (3242)
Review how the Votronic VBCS 30/20/250 Triple CI 3242 connects, how it operates and which installation requirements apply to this model.
Open this example as a new project. Use your own parts and cable lengths to make the plan yours.
Three sources, bidirectional starter terminal, common negative, separate controls and shared mode-dependent output budgets (booster30/mains20/solar18 A); a generic two-bank or shore-only diagram omits essential topology.
Three sources, bidirectional starter terminal, common negative, separate controls and shared mode-dependent output budgets (booster30/mains20/solar18 A); a generic two-bank or shore-only diagram omits essential topology.
Wiring diagram
Open this example in Crimp to use your own parts and cable lengths. Review the assumptions and installation notes as you adapt the circuit.
Installation notes
Guidance for this model, with sources linked beside the relevant advice.
Verified against the manufacturer's documentation (rev. German VBCS Triple CI manual, 11/2020; manufacturer-authored distributor mirror), checked 2026-10-01. Manufacturer documentation →
This record is the 3242 VBCS 30/20/250 Triple CI documented in the November 2020 manual, not a later similar-looking Triple version. It provides up to 30 A from the alternator booster, 20 A from mains and 18 A from the 250 W solar stage. Do not add those numbers together. Mains and solar operation can allocate up to 4 A to starter maintenance within their respective totals. See mode-specific ratings, PDF p. 18.
Bord I positive feeds the house battery; Start II positive carries booster input and reverse-direction starter maintenance. The common negative terminal serves the battery system, and the solar negative returns to that common negative arrangement. Solar positive connects to its dedicated input. The AC input uses line, neutral and protective earth. D+, temperature T/T, voltage sense S+/S−, BMS switching input and CI bus are control circuits, not spare charging outputs. See connection diagram, PDF p. 3.
The 3242 cable table specifies a 50 A starter-side fuse and 40 A house-side fuse. It permits 6 mm² starter cable to 5 m and 6 mm² house positive/negative conductors at 1–2.5 m each. Use the table for the actual layout; a large alternator fuse cannot protect every small sense wire. The diagram separately shows 5 A protection for relevant small feeds. Keep PV below 36 V open circuit, 15 A input and 250 W. See 3242 installation table, PDF p. 6.
Set the house-battery charging program and connect the temperature sensor as instructed. Provide the specified ventilation space. Test mains, real engine/D+ operation and solar separately, recording battery voltage and current for each mode. A voltage-sensing D+ simulator can interact with reverse starter charging and cause cycling; use the vehicle signal specified by the manual. The planner lists the interfaces and mode ratings, but leaves generation unpredicted until source-specific input routing is modeled. Selecting a mode must not make another connected source produce that mode’s current. See startup and troubleshooting, PDF p. 16.
Build it out
Add VBCS 30/20/250 Triple CI (3242) to your diagram, then connect your batteries, chargers and loads. Crimp calculates cable sizes and checks the connections as you draw.
Every cable you draw there is sized against ABYC E-11, from the same tables as the reference on this page.
Technical reference
Check the model, ratings and connection points against your own unit before choosing installation hardware.
Check stud sizes, fuse type, run length and how warm the space gets against the gear you actually have before you order.
Catalog connection points, current direction and planning limits. Check the manufacturer's pinout and connector ratings before installation.
START II +
start-pos
positive · bidi
BORD I +
out-pos
positive · output
COMMON −
out-neg
negative · bidi
SOLAR +
pv-pos
positive · input
AC L
ac-in-l
neutral · input
AC N
ac-in-n
neutral · input
AC PE
ac-in-pe
ground · input
D+
d-plus
signal · bidi
T / T
temp
signal · bidi
S+ / S−
sense
signal · bidi
SW / BMS
bms
signal · bidi
CI BUS
ci
signal · bidi
AES
aes
signal · bidi
A dash means a current rating is not specified here.
Method & provenance
Manufacturer specifications describe the equipment. Crimp calculates cable results from the circuit and assumptions you enter.
From the maker
Manufacturer, model, ratings and which terminal does what come from the catalog. A newer revision, or the nameplate on the unit in your hand, can say something different — when it does, the nameplate wins.
ABYC E-11
Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. The run length and the current above are what drive the result. Crimp doesn't know how warm your space gets; draw the cable inside an engine-bay zone on the canvas and it sizes for the heat.
Next step
Open this example as a new project. Add your equipment and cable lengths, then review the sizing and checks for your setup.